Preparation Of Microcapsules Based On N-docosane Phase Change Material And Its Electrochemical Performance In Supercapacitors

As a new type of electrochemical energy source,supercapacitors have been widely concerned,but due to their use,they will release a lot of heat,causing the material temperature to be too high,resulting in accidents such as combustion and explosion,which limits their application.Phase change materials(PCMs)are a good temperature regulating material,which can absorb and release heat through its own phase change behavior when the outside temperature changes,and maintain its own temperature fluctuation within a small range.In order to regulate the temperature of the supercapacitor when it is working and reduce the occurrence of safety accidents,this paper combines organic PCM with nano-flowered nickel hydroxide to design and prepare a supercapacitor with in-situ thermal regulation Electrode material.On the one hand,the prepared supercapacitor regulates the temperature through the endothermic and exothermic heat of PCM,expands its working temperature range,and effectively improves the working efficiency of the supercapacitor;Electron ions in and out provide a wider ion channel,which has a higher specific capacitance.First,using ethyl orthosilicate as the silicon source and n-docosane as the core material,micron-sized silica microcapsules were synthesized.The prepared microcapsules were characterized by SEM and TEM,indicating that the surface was smooth and dense.It is a typical "core-shell" structure.At the same time,the chemical structure of the microcapsules was confirmed by means of XRD,XPS,EDX,FTIR,etc.DSC,TGA and other means were used to characterize its thermal energy storage performance and thermal stability,and confirmed the phase transition of the synthesized silica The material microcapsules have good energy storage and temperature control effects.Secondly,using PEG-PPG-PEG triblock copolymer P104 as a surfactant and nickel sulfate hexahydrate as a nickel source,the nanoscale nickel hydroxide was loaded on the surface of the silica microcapsules by hydrothermal method,and the external The phase change material microcapsules with nano flower-shaped nickel hydroxide layer were analyzed by SEM,TEM,XRD,XPS,FTIR,DSC,TGA and so on.The results show that the melting enthalpy and crystallization enthalpy of the synthesized target product are 123.4 J/g and 122.8 J/g,which have good energy storage temperature control effect.We prepared the target product as an active electrode and conducted a three-electrode test.It was found that the specific capacitance of the electrode material at 45? and current density of 1.0 A/g was as high as 358 F/g,which was higher than that of nickel hydroxide solid particles at the same temperature and current density It is confirmed that the in-situ temperature control of the phase change material makes the synthesized microcapsule material have excellent electrochemical properties.